Carbon Capture Potential in Lime Modified Kaolin Clay

Abstract

This research presents the potential of combined carbon capture alongside compressive strength improvement in carbonated lime treated kaolin clay, and determines the suitability of the strength improvement for application to capping layer in road pavement. Using combined modification and carbonation treatment at controlled air voids, 4.7%-10% calcium carbonate was determined in kaolin treated with 4-8% calcium hydroxide contents in samples at 10% air voids. Strength increase was achieved in carbonated lime-treated kaolin from 170 kPa to 280 kPa compared with soaked non-carbonated lime treated kaolin, which shows significant increase of approximately 65%. This method of combined modification and carbonation in lime treated clay has the potential to capture carbon alongside improving the strength of the weak kaolin, and could be effectively used for combined carbon capture and road pavement functions.

Carbon Capture Potential in Waste Modified Soils: A Review

“…Previous studies have been conducted on carbonation processes in lime alone (De Silva et al, 2006), lime treated soils (Iorliam et al, 2021;Cizer et al, 2010;Al-Mukhtar et al, 2010) and cement treated soils (Nakarai & Yoshida, 2015). The summary of the carbonation processes is presented in Table 3.…”

“…The report shows that carbonation of lime decreases with increasing compacted density. Also, the degree of carbonation (DOC) of lime is usually less than 100% (De Silva et al, 2006;Iorliam et al, 2021). The DOC refers to the experimentally determined carbonates of cation-rich materials compared to the amount of carbonates that would be formed if a complete carbonation of available cations was achieved (Matsushita et al, 2000).…”

“…Combined optimum carbonation and strength improvement in lime treated soil is achieved at controlled air voids (Iorliam et al, 2021). In lime-pozzolana mortars, there exists a competition for lime between hydration and carbonation reactions.…”

“…Basically, 𝐶𝑎𝐶𝑂 3 content is determined by measuring the gas volume of 𝐶𝑂 2 which results from the reaction process of hydrochloric acid with soil lime. Recently, most studies used the Eijkelkamp calcimeter (volumetric calcimeter) to determine the content of carbonate formed in soil (Washbourne et al, 2015;Iorliam et al, 2021). Another important instrument for the measurement of carbonates formed in clay is thermogravimetric analysis (TGA).…”

“…The use of lime in combined carbonation and modification of clay for carbon capture alongside compressive strength improvement have been established (Iorliam et al, 2021;Iorliam, 2018). The improved soil could serve as combined carbon capture and road pavement function (Iorliam et al, 2021). However, the production of lime itself produces additional carbon dioxide (𝐶𝑂 2 ) emissions (Stork et al, 2014).…”